Table 3 The calculated area ratios of the IR bands, their biomolecular origins and indications.

A₃₀₁₀/A_{2957+2923+2852+1453}

ν(Olefinic = CH)/Total lipid

Unsaturated lipid content

A₃₀₁₀/A_2923+2852

ν(Olefinic = CH)/ν_as(CH₂)+ ν_s(CH₂)

Unsaturated/saturated lipids

A₁₇₄₀/A_2923+2852

ν(C = O)/ν_as(CH₂) + ν_s(CH₂)

Carbonyl group amount in lipids

A₂₉₂₃/A₂₉₅₇

ν_as(CH₂)/ν_as(CH₃)

Aliphatic chain length

A_2923+2852/A_1643+1542

ν_as(CH₂) + ν_s(CH₂)/Amide I + amide II

Lipid/protein

A₁₆₄₃/A_1643+1542

Amide I/Amide I + Amide II

Protein concentration

A₁₂₃₆/A₂₉₅₇

ν_as(PO₂^–)/ν_as(CH₃)

Protein phosphorylation

A₁₅₄₂/A₁₃₄₀

Amide II/A₁₃₄₀

Collagen integrity

A₉₉₀/A_1236+1079

ν(C-O), δ(C-N-C)/ν_as(PO₂^–) + ν_s(PO₂^–)

RNA/PO₂^– antisym. + sym. stretching

A_1236+1079/A_1643+1542

ν_as(PO₂^–) + ν_s(PO₂^–)/Amide I + amide II

PO₂^– antisym. + sym. stretching/protein

A₁₀₃₅/A_1643+1542

ν(C–O) of carbohydrates/Amide I + Amide II

Glucose/protein

A₁₀₃₅/A₁₀₇₉

ν(C–O) of carbohydrates/ν_s(PO₂^–)

Metabolic turnover